The Dysregulated Pharmacology of Clinically Relevant ESR1 Mutants is Normalized by Ligand-activated WT Receptor

The estrogen receptor (ER/ESR1) is expressed in a majority of breast cancers and drugs that inhibit ER signaling are the cornerstone of breast cancer pharmacotherapy. Currently, aromatase inhibitors are the frontline endocrine interventions of choice although their durability in metastatic disease is limited by activating point mutations within the ligand-binding domain of ESR1 that permit ligand-independent activation of the receptor. It has been suggested that the most commonly occurring ESR1 mutations would likely compromise the clinical activity of selective estrogen receptor downregulators and selective estrogen receptor modulators (SERMs) when used as second-line therapies. It was unclear, however, how these mutations, which are likely coexpressed in cells with ER^WT, may impact response to ER ligands in a clinically meaningful manner. To address this issue, we dissected the molecular mechanism(s) underlying ESR1-mutant pharmacology in models relevant to metastatic disease. These studies revealed that the response of ESR1 mutations to ligands was dictated primarily by the relative coexpression of ER^WT in cells. Specifically, dysregulated pharmacology was only evident in cells in which the mutants were overexpressed relative to ligand-activated ER^WT; a finding that highlights the role of allelism in determining ER-mutant pharmacology. Importantly, we demonstrated that the antagonist activity of the SERM, lasofoxifene, was not impacted by mutant status; a finding that has led to its clinical evaluation as a treatment for patients with advanced ER-positive breast cancer whose tumors harbor ESR1 mutations.

G1T48, an oral selective estrogen receptor degrader, and the CDK4/6 inhibitor lerociclib inhibit tumor growth in animal models of endocrine-resistant breast cancer

Purpose

The combination of targeting the CDK4/6 and estrogen receptor (ER) signaling pathways with palbociclib and fulvestrant is a proven therapeutic strategy for the treatment of ER-positive breast cancer. However, the poor physicochemical properties of fulvestrant require monthly intramuscular injections to patients, which limit the pharmacokinetic and pharmacodynamic activity of the compound. Therefore, an orally available compound that more rapidly reaches steady state may lead to a better clinical response in patients. Here, we report the identification of G1T48, a novel orally bioavailable, non-steroidal small molecule antagonist of ER.

Methods

The pharmacological effects and the antineoplastic mechanism of action of G1T48 on tumors was evaluated using human breast cancer cells (in vitro) and xenograft efficacy models (in vivo).

Results

G1T48 is a potent and efficacious inhibitor of estrogen-mediated transcription and proliferation in ER-positive breast cancer cells, similar to the pure antiestrogen fulvestrant. In addition, G1T48 can effectively suppress ER activity in multiple models of endocrine therapy resistance including those harboring ER mutations and growth factor activation. In vivo, G1T48 has robust antitumor activity in a model of estrogen-dependent breast cancer (MCF7) and significantly inhibited the growth of tamoxifen-resistant (TamR), long-term estrogen-deprived (LTED) and patient-derived xenograft tumors with an increased response being observed with the combination of G1T48 and the CDK4/6 inhibitor lerociclib.

Conclusions

These data show that G1T48 has the potential to be an efficacious oral antineoplastic agent in ER-positive breast cancer.

Electronic supplementary material

The online version of this article (10.1007/s10549-020-05575-9) contains supplementary material, which is available to authorized users.

Androgen receptor antagonism drives cytochrome P450 17A1 inhibitor efficacy in prostate cancer

The clinical utility of inhibiting cytochrome P450 17A1 (CYP17), a cytochrome p450 enzyme that is required for the production of androgens, has been exemplified by the approval of abiraterone for the treatment of castration-resistant prostate cancer (CRPC). Recently, however, it has been reported that CYP17 inhibitors can interact directly with the androgen receptor (AR). A phase I study recently reported that seviteronel, a CYP17 lyase-selective inhibitor, ædemonstrated a sustained reduction in prostate-specific antigen in a patient with CRPC, and another study showed seviteronel's direct effects on AR function. This suggested that seviteronel may have therapeutically relevant activities in addition to its ability to inhibit androgen production. Here, we have demonstrated that CYP17 inhibitors, with the exception of orteronel, can function as competitive AR antagonists. Conformational profiling revealed that the CYP17 inhibitor-bound AR adopted a conformation that resembled the unliganded AR (apo-AR), precluding nuclear localization and DNA binding. Further, we observed that seviteronel and abiraterone inhibited the growth of tumor xenografts expressing the clinically relevant mutation AR-F876L and that this activity could be attributed entirely to competitive AR antagonism. The results of this study suggest that the ability of CYP17 inhibitors to directly antagonize the AR may contribute to their clinical efficacy in CRPC.

A study of antagonist affinities for the human histamine H2 receptor

BACKGROUND AND PURPOSE

Ligand affinity has been a fundamental concept in the field of pharmacology and has traditionally been considered to be constant for a given receptor-ligand interaction. Recent studies have demonstrated that this is not true for all three members of the G(s)-coupled beta-adrenoceptor family. This study evaluated antagonist affinity measurements at a different G(s)-coupled receptor, the histamine H(2) receptor, to determine whether antagonist affinity measurements made at a different family of GPCRs were constant.

EXPERIMENTAL APPROACH

CHO cells stably expressing the human histamine H(2) receptor and a CRE-SPAP reporter were used and antagonist affinity was assessed in short-term cAMP assays and longer term CRE gene transcription assays.

KEY RESULTS

Nine agonists and seven antagonists, of sufficient potency at the H(2) receptor to examine in detail, were identified. Measurements of antagonist affinity were the same regardless of the efficacy of the competing agonist, time of agonist incubation, cellular response measured or presence of a PDE inhibitor.

CONCLUSIONS AND IMPLICATIONS

Antagonist affinity at the G(s)-coupled histamine H(2) receptor obeys the accepted dogma for antagonism at GPCRs. This study further confirms that something unusual is indeed happening with the beta-adrenoceptors and is not an artefact related to the transfected cell system used. As the human histamine H(2) receptor does not behave in a similar manner to any of the human beta-adrenoceptors, it is clear that information gathered from one GPCR cannot be simply extrapolated to predict the behaviour of another GPCR. Each GPCR therefore requires careful and detailed evaluation on its own.

Reporter-gene systems for the study of G-protein-coupled receptors

Reporter-gene assays offer an alternative to biochemical assays for following signal transduction pathways from receptors at the cell surface to nuclear gene transcription in living cells. Specific reporter-gene systems are now available for the study of ligand activity at G alpha(i/o), G alpha(s) and G alpha(q) G-protein-coupled receptors. In recent years reporter genes have been applied in academia and industry to the study of ligand efficacy and affinity in recombinant and primary cell lines using a variety of colour, fluorescent or luminescent read-outs.

Adolescent girl's coping with an STD. Not enough problem solving and too much self-blame

STUDY OBJECTIVE

Approximately three million teenagers are infected with an STD each year. The ways in which an adolescent girl copes with an STD may have implications for future risk and for psychological adjustment. The purpose of the current study was to compare whether coping with an STD was similar to coping with other stressors.

SETTING

Urban, hospital-based adolescent medicine clinic.

DESIGN AND PARTICIPANTS

Sixty-seven girls with a mean age of 15.9 (sexual debut was 13.8) yr completed the KIDCOPE in response to both an STD acquisition and an interpersonal stressor within the previous 6 months.

RESULTS

Problem solving was used less often, and self-blame was used more often, in response to an STD acquisition. Frequency of use of self-blame was not correlated with perceived helpfulness.

CONCLUSIONS

These findings suggest that clinicians need to help adolescent girls manage STD acquisition from the perspective of problem solving rather than self-blame.

Engaging community mental health stakeholders in pharmacy cost management

To improve the cost-effectiveness of psychotropic medications, a process was established to involve all stakeholders in a seven-county public-sector behavioral health managed care plan in the development of formulary guidelines. After delineation of the issues and of possible strategies, proposed formulary guidelines were drafted and presented to the stakeholders in a series of meetings. The stakeholders were also educated about pharmacy cost management issues and possible strategies. The guidelines were modified on the basis of the feedback obtained from stakeholders, and the consensus formulary guidelines were adopted. Within ten weeks of implementation of the guidelines, monthly medication costs had declined by 3 percent from baseline, although the number of medication users increased by 3 percent over the same period. There were few complaints about the guidelines. Effective, consensus-driven, medication cost-containment strategies can be implemented through a process of engagement and education of stakeholders in a community mental health plan.

Prevalence and identification of problems in daily functioning in a primary medicine clinic

PURPOSE

This pilot study compares scores on a health status/functional assessment measure to clinician identification of problems in functioning and referrals for these problems, based on examination of information in the patient's medical chart.

METHOD

A sample of 194 participants at a primary medicine clinic in an urban general hospital completed a measure of health status and functioning, the Medical Outcomes Trust Short Form 36 (SF-36). Chart reviews were conducted to assess whether problems in functioning were addressed by the primary care clinician.

RESULTS

Overall, levels of functioning on the scales of the SF-36 were well below norms for the general US population from the Medical Outcomes Study. Older adults showed lower physical functioning and higher emotional functioning than younger adults. Participants with 1, 2, or 3 chronic conditions showed increasingly lower levels of physical functioning. For participants with functional assessment scale scores in the lowest quartile, problems in functioning noted in the chart ranged from 13%-28%. Only 6% 20% of participants with marked problems in functioning were referred for further assessment or treatment.

CONCLUSIONS

Functional problems are frequently important indicators of risk of development of secondary complications and need for referral. Questionnaire screening may increase identification and referral for problems in functioning in primary care settings.

Using quality improvement teams to improve documentation in records at a community mental health center

OBJECTIVE

A community mental health center sought a system for qualitative review of patients' records to improve the quality of documentation through the engagement of clinical staff in the review process.

METHODS

The center developed a quality improvement system in which treatment team clinicians use a scored 30-item protocol to measure the quality of record documentation by peers. Questions address whether the record documents the full range of the psychiatric treatment process, including assessment and diagnosis, treatment planning, and provision of clinical services. Other questions address specific contractual or regulatory requirements, such as whether procedure codes are correct, and evaluate the physician's record of medication management. Each treatment team at the mental health center's six clinics has a quality improvement work group, composed of the team psychiatrist and at least one other team clinician. Each month the work group meets to review two randomly selected medical records from another treatment team at the same clinic and arrive at a consensus score. An administrative oversight team meets regularly with clinician-reviewers to foster uniform scoring of the protocol throughout the center.

RESULTS

An analysis of the trend in protocol scores over a 21-month period suggests that the procedure improves the quality of the documentation in patients' records.

CONCLUSIONS

A team-based quality review process appears to have a positive impact on the quality of medical record documentation. Improved documentation may improve continuity of care and improve the accuracy of record information used for other quality measurement systems.

Photographic optical systems with nonrotational aspheric surfaces

Sections of nonrotational aspheric surfaces can be useful in a variety of optical situations. In several examples, image-forming objectives, as for photographic or electronic camera products, are described in which suitably located asymmetric pairs of refractive surfaces are devised, such that relative rotation about a displaced axis of one with respect to the other can be used to produce a focusing effect that is satisfactory for imaging purposes over reasonable fields of view and for practicable apertures and achromatic corrections. Taylor expansions about assignable reference points in any given surface of a sequence, together with suitable coordinate systems, can be employed to relate performance to shape parameters.

Perceived ideological differences, job satisfaction and organizational commitment among psychiatrists in a community mental health center

Physician turnover has long been a problem in community mental health centers. While explanations for the problem have been offered, there have been no systematic studies of factors associated with the high turnover. In this study, the Minnesota Satisfaction Questionnaire and the Organizational Commitment Questionnaire were given to psychiatrists employed by a community mental health center. Subjects were also asked to identify their treatment ideology, and to rate their perception of the ideology of other clinicians and administrators with whom they work. Psychiatrists perceived significant differences in many ideological areas. Analysis demonstrated a correlation between these differences and the commitment of the psychiatrists to the organization.

Relationship between perceived parental monitoring and young adolescent girls' sexual and substance use behaviors

STUDY OBJECTIVE

The purpose of the study was to examine the independent effects of perceived parental monitoring on sexual experience, contraceptive, and substance use.

DESIGN, SETTING, AND PARTICIPANTS

Adolescent females at an urban-based adolescent clinic (N = 174; 41% sexually experienced) rated the extent to which they were directly and indirectly monitored by their parents.

MAIN OUTCOME MEASURES

These perceptions were compared with reported contraceptive use as well as substance use. Direct parental monitoring was best described using two dimensions: direct monitoring and direct monitoring when with peers.

RESULTS

Direct monitoring was found to be associated with the use of hormonal birth control methods at last intercourse. Direct parental monitoring when with peers was found to be associated with less use of alcohol and cigarettes.

CONCLUSIONS

These data suggest that parental monitoring is a relevant factor for primary care physicians to explore during treatment.

Predicting follow-up functional outcomes in outpatient rehabilitation

Functional outcomes at an average of six months after outpatient rehabilitation were investigated in a pilot study with a sample of 42 patients receiving physical therapy for low back, neck, and other musculoskeletal problems. Logistic regression analyses were used to study variables related to the achievement of a predetermined level of physical functioning or to whether improvement occurred from initial to follow-up assessment. Scales used in the analyses were obtained from two measures of functioning, the Medical Outcomes Trust Short Form 36 (SF-36) and the Medical Rehabilitation Follow Along (MRFA instrument). Demographic and program characteristic variables obtained from clinic records were also included in the analyses. The independent variables entered into two groups of regression equations included age, gender, presenting problem, workers' compensation coverage, functioning at initial assessment, number of visits, length of program, and intensity of program. For the SF-36, the General Health scale and presenting problem predicted above or below a level greater than one standard deviation less than the mean on the Physical Functioning scale at follow-up. The combination of the Role Physical and Role Emotional scales predicted follow-up level on the Physical Component Summary (PCS) scale. The interaction of age and intensity of treatment was predictive for both the Physical Functioning and PCS scales. For predicting improvement or no improvement using the SF-36 scales, General Health and the interaction between age and intensity were predictive of change on the Physical Functioning scale, whereas age and the interaction between age and number of visits were predictive of change on the PCS scale. For the MRFA instrument, the interaction between age and the intensity of treatment was predictive for both a predetermined level of physical functioning and amount of improvement in physical functioning at follow-up. An intensity rating of pain and a measure of affective distress at initial assessment both improved the identification of patients at risk for not reaching a given level of functioning, whereas treatment intensity improved the identification of those patients at risk for not showing improvement at follow-up. Length of time between the end of outpatient therapy and follow-up assessment was generally not related to follow-up physical functioning. Interpretation and implications of these findings, as well as applications of this analytic approach to outcomes assessment, are discussed.

The development of prejudice towards gays and lesbians by adolescents

The authors studied the development of gay and lesbian prejudice in white, suburban adolescents in grades 7, 9, and 11. Results parallel several major findings with adults: males were more prejudiced than females; this difference was greater towards gay males than lesbians; and same-sex prejudice was greater than opposite-sex prejudice. For males and females prejudice increased between grades 7 and 9, but from grades 9 to 11 it decreased for females and increased for males. These differences were explained by the increased vulnerability of males to defensive reactions in response to the prospect of intimate relationships. None of the personality measures were significantly correlated with prejudice.

A spreadsheet method for calculating maximum caseload and intake capacity for CMHC psychiatrists

OBJECTIVE

A method was sought to help administrators of community mental health centers determine a level of psychiatric staffing that is both cost-efficient and ensures high quality of care.

METHODS

A survey of staff psychiatrists was conducted at a large community mental health center with seven outpatient clinics. The survey measured variables that can affect staffing requirements, including the number of hours psychiatrists have available for direct care, their preferred intervals between a patient's return visits, and the duration of appointments for an initial psychiatric assessment and for medication maintenance. A computer spreadsheet was developed to calculate the caseload capacity and intake capacity for clinics of the center.

RESULTS

The survey indicated that the psychiatrists at the center had an average of 33 hours a week available for direct care. The mean preferred time between a patient's medication maintenance visits was 7.3 weeks. The mean time required for a psychiatric assessment was 80 minutes, and for a medication maintenance visit it was 33 minutes. With these data, the spreadsheet method was used to calculate intake and caseload capacity for psychiatric staff at three of the center's clinics.

CONCLUSIONS

The data-based approach to calculating capacity can be modified to meet local needs. It brings objectivity to decision making about staffing, and the methods can improve resource management and enhance relationships between stakeholders and physicians.

A brief outpatient functional assessment measure: validity using Rasch measures

The Medical Rehabilitation Follow Along (MRFA(TM)) is a brief outpatient functional assessment measure that was developed using Rasch analysis. The MRFA currently has musculoskeletal, neurologic, multiple sclerosis, cardiac, and pulmonary forms. Using Rasch scoring and selected scales, the 31-item musculoskeletal form of the MRFA was compared with and contrasted to a measure of general health status, the Medical Outcomes Trust SF-36. Content, construct, and criterion validity were addressed using scale scores before and after outpatient rehabilitation, as well as therapist ratings of improvement. The results supported the validity of inferences made from the MRFA scales using Rasch measures for persons with musculoskeletal problems. Rasch and raw scoring provided similar results with respect to the validity of the MRFA scales. Implications for the use of Rasch and raw scoring approaches with the MRFA are discussed.

Validity of a brief outpatient functional assessment measure

Aspects of validity are investigated with a brief functional assessment measure among outpatients undergoing rehabilitation for musculoskeletal problems. The Medical Rehabilitation Follow Along measure (MRFA) currently has screening, musculoskeletal, neurologic, and multiple sclerosis forms. In this study, the 31-item musculoskeletal form of the MRFA is compared with and contrasted to a measure of general health status, the Medical Outcomes Trust SF-36. Content, construct, and criterion validity are addressed using scale scores before (n = 94) and after (n = 48) outpatient rehabilitation. Scale scores are compared with therapists' ratings of improvement. The results provide support for the validity of inferences made from scale scores of the MRFA for persons with musculoskeletal problems. Applications of the MRFA, including screening, monitoring, and outcome assessment are discussed for clinical management, measuring treatment effectiveness, and program evaluation.

Memory and emotion processing in cortical and subcortical dementia

Findings from studies of implicit-memory dissociations, emotion processing, and emotion-memory phenomena were integrated with reference to distinctions between so-called cortical and subcortical dementia. Hemispheric distinctions and implications for normal psychological processes are discussed.

Reliability of a brief outpatient functional outcome assessment measure

The stability of the musculoskeletal form of the Medical Rehabilitation Follow Along (MRFA) instrument was examined in 47 patients receiving outpatient rehabilitation services. The MRFA instrument was designed to provide information on quality of daily living, including physical function, pain, satisfaction, and emotional/psychological well-being. The instrument consists of thirty questions and can be administered as an interview or a written questionnaire. The MRFA instrument was developed using Rasch analysis procedures and is an extension of previous research involving the Functional Assessment Screening Questionnaire. Forty-seven patients completed the musculoskeletal form of the MRFA on two occasions separated by an interval of 1 to 7 days. The stability of responses was examined using the intraclass correlation coefficient (ICC) and kappa. ICC values for the sections of the MRFA instrument examining quality of daily living and physical functioning ranged from 0.74 to 0.97. ICC values for items assessing pain and feelings of well-being were more variable, ranging from 0.36 to 0.93. The kappa values displayed a similar pattern. The overall stability of the MRFA instrument was found to be adequate for gathering screening information in outpatient settings. Additional research is necessary to confirm the findings of this investigation and extend the results to a larger outpatient population.

Monitoring in methadone maintenance treatment

Weekly preannounced and unannounced urine testing was compared in a counterbalanced design with two random samples of clients (n = 74) from a methadone maintenance program. Results indicated no significant differences in the detected rate of positive specimens for the two types of testing. Clients reported preference for the preannounced testing and indicated that testing was not very helpful in avoiding the use of illicit drugs. The merits of psychosocial procedures in response to the outcome of monitoring are discussed.

Reasons for condom utilization among high-risk adolescent girls

Two hundred forty-eight adolescent girls responded to a list of 30 statements describing reasons for using and not using condoms. For 24 of the statements, most adolescents (> 70%) gave the same response regarding why they did or did not use condoms. Therefore, only the six remaining statements were used in further analyses. The relationship between the six statements and psychosexual history, condom use, and sexually transmitted disease (STD) history was examined. Those adolescent girls who had been sexually active longer were more likely to report lack of enjoyment as a reason that they did not use condoms (P < .03), and those adolescents who had been sexually active less time were more likely to report personal (P < .005) and partner (P < .0006) enjoyment of sex with condoms as a reason for using condoms. Longer relationships before intercourse were associated with having condoms available (P < .01) and partner insistence on their use (P < .02). Partner insistence on condom use was related to fewer episodes of sexually transmitted diseases (P = .03). These findings indicate the importance of relationship and partner variables in adolescent girls' perceptions of condom use.

AIDS and competing health concerns of blacks, Hispanics, and whites

Blacks, Hispanics, and whites were interviewed in a door-to-door survey assessing personal concern about AIDS relative to other health threats and willingness to attend in-home AIDS education programs. The survey consisted of three parts: (1) an open-ended inquiry regarding which health problems individuals wanted to learn more about, (2) ratings of concern about AIDS and nine other common health threats, and (3) assessment of willingness to participate in future neighborhood-based AIDS education programs. Usable data were obtained from 453 respondents. Sixty-seven health threats were mentioned in response to the open-ended inquiry; AIDS was mentioned by 50.7%, followed by cancer (19.9%). AIDS was mentioned more frequently by blacks (63.9%) than by Hispanics (42.5%) or whites (45.7%), X2(3) = 32.07, p less than .002. Participants also reported higher levels of concern about AIDS than any other health problem with the exception of cancer. Concern about AIDS was greater among blacks (M = 2.68) than among Hispanics (M = 2.33) or whites (M = 2.36), F(2,351) = 5.06, p less than .01. Differences as a function of ethnicity, gender, and/or age were observed with respect to concern about heart disease, high blood pressure, diabetes, drug abuse, colds and flu, and herpes. In general, blacks and Hispanics expressed more interest in participating in AIDS education programs than did whites. Concern about AIDS and other health threats was not consistently related to either disease prevalence or severity.

Frontal sinus osteoma with complicating intracranial aerocele

An elderly man, who presented initially with clinical features of dementia, was found to have an intracranial tension aerocele due to an underlying osteoma of the frontal sinus. Plain skull roentgenograms and computerized tomography did not reveal the osteoma, although a communication between the frontal sinus and the aerocele was present. Surgical aspiration of the aerocele and excision of the osteoma produced an excellent clinical result.

Episodic effects on picture identification: implications for theories of concept learning and theories of memory

The effects of differences in study processing on free recall of picture names and on generalization in picture identification were investigated. Experience with degraded pictures produced poorer subsequent free recall of picture names than did naming intact pictures. For the test of picture identification, pictures that were identical to a studied picture, pictures that shared a name with a studied picture (same name), and new test pictures were presented, and the amount of clarification required to identify a picture was measured. Experience with degraded pictures produced better subsequent identification of identical test pictures but poorer later identification of same-name test pictures than did naming intact pictures. The importance of these episodic effects for theories of concept learning and theories of memory is discussed. It is argued that distinctions between memory systems (e.g., episodic-semantic) must be couched in terms of a theory of concept learning and that the data are inconsistent with a simple distinction.

Episodic effects on picture identification: Implications for theories of concept learning and theories of memory

The effects of differences in study processing on free recall of picture names and on generalization in picture identification were investigated. Experience with degraded pictures produced poorer subsequent free recall of picture names than did naming intact pictures. For the test of picture identification, pictures that were identical to a studied picture, pictures that shared a name with a studied picture (same name), and new test pictures were presented, and the amount of clarification required to identify a picture was measured. Experience with degraded pictures produced better subsequent identification of identical test pictures but poorer later identification of same-name test pictures than did naming intact pictures. The importance of these episodic effects for theories of concept learning and theories of memory is discussed. It is argued that distinctions between memory systems (e.g., episodic-semantic) must be couched in terms of a theory of concept learning and that the data are inconsistent with a simple distinction.

First report of subcutaneous phaeohyphomycosis of the foot caused by Phoma minutella

Phoma minutella, a dematiaceous hyphomycete, was isolated to the exclusion of all other fungi from a subcutaneous inflammatory process on the foot of a farmer undergoing corticosteroid therapy for myasthenia gravis. Isolation was achieved on several nutrient media. Examination of stained smears and sections revealed dematiaceous fungal elements consistent with the mold. This is the first reported association of P. minutella with a human infection and only the second reported case involving a Phoma sp. as the etiologic agent of a subcutaneous infection.

Candida lusitaniae: a new opportunistic pathogen of the urinary tract

A 78-year-old man with mild diabetes presented with dysuria and frequency of urination of 15 months' duration subsequent to urinary catheterization for cataract surgery. Multiple urine specimens revealed the presence of considerable quantities of yeast that were later identified as Candida lusitaniae. The patient responded well to irrigation of the bladder with amphotericin B.

Pathogenicity of Candida paratropicalis

A new Candida species, Candida paratropicalis, was recently described. Four cases of infections due to C paratropicalis are reviewed in detail and an additional five cases are reviewed to establish the clinical relevance of this species of yeast. Candida paratropicalis was isolated from blood and several other body sites. Although the isolates tested were sensitive in vitro to amphotericin B and fluocytosine, significant morbidity and mortality were associated with the infections.

Use of rapid auxanographic procedures for recognition of an atypical Candida

An atypical Candida which can cause diagnostic problems in clinical laboratories has recently been characterized. Assimilation patterns of 29 clinical isolates of an atypical Candida were obtained by the API 30C (Analytab Products, Plainview, N.Y.)., Uni-Yeast-Tek (Flow Laboratories, Inc., Rockville, Md.), and dye pour-plate auxanographic methods. The low frequency of assimilation of cellobiose, sucrose, and melezitose noted in all of these procedures permitted the early recognition of the atypical character of the isolates.

Diagnostic characters of an atypical Candida

The morphological and physiological characters of an atypical Candida isolated from diverse clinical specimens are described. The colony and microscopic morphologies of the atypical Candida most closely resemble those of Candida tropicalis or of reported sucrose-negative variants of C. tropicalis. However, the atypical isolates differ from C. tropicalis by their inability to ferment sucrose or melezitose and from the sucrose-negative variants by their inability to assimilate inulin and their varied utilization of other carbon substrates.

Rapid identification of Prototheca species by the API 20C system

The conventional auxanographic method of testing for the assimilation of carbohydrates and alcohols by the various species of Prototheca requires at least 2 weeks of incubation at 25 to 30 degrees C before definitive results are obtained. Even though Prototheca spp., in culture as well as in fixed tissues, can be identified more rapidly by fluorescent-antibody techniques in which species-specific reagents are used, such diagnostic facilities and reagents are not available in most diagnostic laboratories. The API 20C clinical yeast identification system, a commercially available ready-to-use micromethod, was found to permit the definitive identification of P. stagnora, P. wickerhamii, and P. zopfii within 4 days.

Spontaneous alternation and the influence of reward

The experiment studied the effects of number of rewards and stimulus change upon spontaneous alternation. Rats were given 0, 4, 8, and 16 non-forced food-rewarded trials to a given alternative of a T maze, after which the non-rewarded stimulus alternative was changed to a checkerboard pattern for half of the Ss. Alternation decreased with increasing number of reinforced trials, 80, 90, 60, and 30%, respectively, for the four reward conditions; however, Ss that received a change in the non-rewarded alternative alternated at a high rate, 80, 100, 80, and 80%, respectively, for the four reward conditions. The results pose a problem for traditional drive-reduction and food-incentive interpretations of learning as well as for satiation theories of spontaneous alternation.